Hello,

Please add this code into your custom css box:

@media (max-width: 480px){
ul.tp-revslider-mainul {
    width: 370px !important;
    left: -10% !important;
}}
@media (max-width: 767px){
ul.tp-revslider-mainul {
    width: 585px !important;
    left: -10% !important;
}}

Let us know.

Best regards!

Hello,

Please edit the values of css attributes (decrease/increase) until you are satisfied with the result.

Best regards!

Hello,

Do you mean, have full width slider in mobile but boxed in desktop? This is not possible via theme settings. The only way is to change slider width in desktop with custom css.
Try this code:

@media (min-width: 1600px){
#rev_slider_6_1_wrapper {
    width: 1100px !important;
    left: 10px !important;
    height: 800px !important;
}
.fullwidthbanner-container .fullwidthabanner  { height: 800px !important;}
#rev_slider_6_1_forcefullwidth {  height: 800px !important;}
.wpb_revslider_element.wpb_content_element { height: 800px !important;}
}

Result screenshot.

Best regards!